Heraclitus of Ephesus (fl. 500-480 BC), also known as "the Riddler" and "the Obscure," was the eldest son of a leading aristocratic family. He was a loner with a general distaste for mobs. Consequently, he had no pupils, though a small book that he wrote had a rich tradition of its own and attracted many followers; the Stoics recognized it as the source of their doctrines. All that survives of this book is a series of quotations that scholars have been able to extract from other sources -- see the Fragments of Heraclitus -- and that reveal an enigmatic and oracular style, perhaps adopted by Heraclitus to protect its true contents from commoners. Owing to its obscurity, the book engendered many anecdotes about its author, most of them intending to malign him, and so it is difficult to know much about his life and character that is reliable. It is equally difficult to discern the details of his true thought.